Collaborative Research: Genesis of Primitive, High-Sr Lavas in the Western Aleutians

智力优势：这项研究是四个机构的合作，支持在2005年7月至8月进行的一次巡航期间通过疏浚阿留申群岛西部海底的火山岩收集的火山岩的地球化学研究。 初步结果表明，岩石中含有大量原始熔岩，不仅包括玄武岩，还包括具有不寻常微量元素成分的安山岩和英安岩。该项目的目标是分析其中的100个样本，并利用这些数据来模拟导致其成因和演化的岩石学和地球化学过程，并将这些结果置于俯冲带岩浆过程的背景下。 分析工作将侧重于全岩地球化学，包括主要元素和微量元素，确定100个样品中一部分的Pb、Sr、Nd和Hf同位素比率，对一些最新鲜的含玻璃质熔岩中的斑晶和玻璃夹杂物进行电子显微探针研究，并使用离子探针确定辉石斑晶和橄榄石和辉石中的玻璃夹杂物的微量元素组成。华盛顿卡内基研究所的一名合作者将对玻璃夹杂物中的挥发性和轻元素进行一项小型、无成本的试点研究。更广泛的影响：这项研究涉及四个机构之间的合作，并将支持博士生和本科生在南卡罗来纳州，这是一个EPSCoR国家的大学。 该项目还聘请了一名新的海洋科学研究人员。 地球化学分析将支持共用分析设施，从而帮助维持科学基础设施。 数据将存档，并在众所周知的地球化学数据库中向公众提供，包括GeoRock和PetDB。

Intellectual Merit: This research is a four-institution collaboration that supports geochemical studies of volcanic rocks collected by dredging volcanic the western Aleutian seafloor during a cruise carried out in July-August 2005. Preliminary results show that the rocks contain a large proportion of primitive lavas that include not only basalts, but also andesites and dacites with unusual trace element compositions. Goals of the project are to analyze 100 of these samples and use the data to model the petrological and geochemical processes leading to their genesis and evolution and placing these results in the context of subduction zone magmatic processes. Analytical efforts will focus on whole-rock geochemistry including major and trace elements, determine Pb, Sr, Nd and Hf isotopic ratios on a subset of the 100 samples, carry out electron microprobe studies of phenocrysts and glass inclusions in some of the freshest glass-containing lavas, and use the ion probe to determine trace element compositions of pyroxene phenocrysts and glass inclusions hosted by olivine and pyroxene. A small, no-cost pilot study of volatile and light elements in glass inclusions will be carried out by a collaborator at the Carnegie Institution of Washington. Broader Impacts: This research involved collaboration between four institutions and will support a PhD student and undergraduates at a university in South Carolina, which is an EPSCoR state. The project also engages a new investigator in ocean science. Geochemical analyses will support shared use analytical facilities thereby helping sustain the infrastructure for science. Data will be archived and made available to the public on well know geochemical databases, including GeoRock and PetDB.